1. Field of the Invention
The present invention relates to a camera for taking images such as moving images and still images, and in particular to an image shake correction apparatus incorporated in a camera which operates to compensate for handheld camera shake that occurs in the vertical and horizontal directions of the camera at a time of exposure.
2. Description of the Related Art
An image shake correction apparatus which compensates for handheld camera shake by finely moving an image sensor (image pickup device) in a plane orthogonal to the optical axis in the horizontal direction (X-direction) and the vertical direction (Y-direction) of the camera has been proposed for a camera, e.g., for a digital camera that takes still images using an image sensor. Although various configurations for making an image sensor move in the X and Y directions in such a manner have been proposed, and among these configurations the employment of a so-called “X-Y stage” is effective for simplifying the image shake correction apparatus. An X-Y stage includes a Y-table movable in the Y-direction relative to a stationary base plate and an X-table movable in the X-direction relative to the Y-table, and an image sensor is mounted on the X-table, which makes it possible to move (reciprocate) the image sensor in the X and Y directions relative to the stationary base plate. For instance, this type of image shake correction apparatus is disclosed in Japanese Unexamined Patent Publication 2006-208702, specifically in the embodiment shown in FIG. 9 thereof, in which a Y-direction moving plate is supported to be movable in the Y-direction by a pair of Y-direction guide bars fixed to a stationary support base plate, and the Y-direction moving plate is driven to move in the Y-direction by a Y-direction drive system including a coil and a magnet. In addition, an X-direction moving plate that holds a CCD is supported to be movable in the X-direction by a pair of X-direction guide bars fixed to the Y-direction moving plate, and the X-direction moving plate is driven to move in the X-direction by an X-direction drive system including a coil and a magnet. Additionally, the magnitude of camera shake which occurs in the camera is detected by a sensor provided in the camera, and the Y-direction moving plate and the X-direction moving plate are moved (driven) by controlling the operations of the X-direction drive system and the Y-direction drive system, respectively, in such a manner as to compensate for the detected magnitude of camera shake. Such movements of the Y-direction moving plate and the X-direction moving plate move the CCD in the X and Y directions to thereby correct image shake caused by hand shake so as to maintain the object image at a constant position on the imaging surface of the image sensor.
In the image shake correction apparatus disclosed in Japanese Unexamined Patent Publication 2006-208702, it is necessary to provide the image shake correction apparatus with a pair of Y-direction guide bars and a Y-direction drive system to move the Y-direction moving plate in the Y-direction in a plane orthogonal to an optical axis of the photographing optical system, and it is also necessary to provide the image shake correction apparatus with a pair of X-direction guide bars and an X-direction drive system to move the X-direction moving plate in the X-direction. Therefore, the number of elements of the image shake correction apparatus is great, which complicates the structure thereof and makes it difficult to miniaturize the image shake correction apparatus. In particular, the pair of Y-direction guide bars are disposed so as to extend along both sides of the Y-direction moving plate, respectively, while the pair of X-direction guide bars are disposed so as to extend along both sides of the X-direction moving plate, respectively, and installation space for these pairs of guide bars must be secured. In addition, installation space must be provided for the Y-direction drive system and the X-direction drive system; however, these spaces make it difficult to miniaturize the image shake correction apparatus.